Reorganized core/ directory, it was too fatty already

-Removed FuncRef, since Callable makes it obsolete
-Removed int_types.h as its obsolete in c++11+
-Changed color names code

core/io/file_access_compressed.cpp

@@ -30,7 +30,7 @@
 
 #include "file_access_compressed.h"
 
-#include "core/print_string.h"
+#include "core/string/print_string.h"
 
 void FileAccessCompressed::configure(const String &p_magic, Compression::Mode p_mode, int p_block_size) {
 	magic = p_magic.ascii().get_data();